Steam rock-drill



(Model) s. G. BRYER. STEAM ROCK DRILL.

Patented Sept. 6, 1881.

A HE E J e W A W m 0/ 2 6 w% w in.

UNITED STATES PATENT OFFICE.

SAMUEL e. BRYFR, or SAUGUS, MASSACHUSETTS.

YSTEAM ROCK-DRILL.-

SPECIFICATION forming part of Letters Patent No. 246,593, dated September'G, 1881. Application filed April 18, 1881. (ModeL) T 0 all whom 'it'may concern:

Beit known that I, SAMUEL G. BRYER, a citizen of the United States, residing at Saugus, in the county of Essex and State of Massachusetts, have invented certain new and useful Improvements in Steam Rock-Drills and I hereby declare that the same are fully described in the following specification andillustratrd in the accompanying drawings.

This invention relates to improvements in Iockdrilling machines; and it consists in the combination, with acylinderand its reciprocating piston that carries the drill or boring-tool, of reciprocating valves located in the front and back heads of the cylinder, so constructed, operated, and arranged as to provide an auxiliary live-steam supply in each end of the cylinder, to aid in reciprocating the piston forward and back, and an auxiliary exhaust in each end of the cylinder, to prevent any accumulation of pressure in each end of the cylinder after the main exhaust is closed. The piston acts as the main valve, and the cylinder is provided with exhaust-ports so situated that before the piston reaches each end of the stroke the exhaust is cut off, thereby causing a back-pressure, which is relieved by the auxiliary valves.

The invention is carried out as follows, reference being had to the accompanying drawings, in which- Figure 1 represents a plan view of the back head and a section of the upper valve. Fig. 2 represents alongitudinal section on the line A B, shown in Fig. 1. Fig. 3 represents a longitudinal section on the line 0 D, also show n in Fig. 1. Fig. 4 represents a cross-section on the line E F, shown in Fig. 2.

' Similar letters refer to similar parts when ever they occur on the different parts of the drawings.

a is the reciprocating piston, movable up and down within the cylinder b. The piston is provided midway with an annular groove, a, serving as a steam-chamber to conduct the live steam to each end of the cylinder.

b is the main steam-inlet to the cylinder 1), communicating with the annular groove to, as shown in Fig. 3. a

The, cylinder bis provided in its back end with a pair of diametrically-opposite located steam-passages, c 0, through which the main steam-supply is conducted to the back end of the cylinder when the piston a is in the position as shown in Fig. 3,-and until it descends, so as to close the lower ends of such passages 00.

(l is the back head of the cylinder 1), in which the valve chamber 0 is located. Within the valve-chamber e is arranged the automatic piston'valvef, as shown.

9 is a small passage leading from one of the steam passages c to the large end of the piston-valvef, as shown in Fig. 2, so as to automatically force the valve f to the right (the position shown in Fig, 2) until the upper end of the piston a, in its downward stroke, reaches the exhaust port h, communicating with the passage 45 and main exhaust 70.

l is the auxiliary steam-passage, leading from the annular groove a to the passage m, into the valve-chamber e, and thence through passage a into the back end ofthe. cylinder b, as shown in Figs. 1 and 2, and thus live steam is admitted through such auxiliary passages to aid in forcing the piston Ct downward until the upper end thereof reaches its exhaust-port 11-, when the pressure is relieved at the left-hand end of the valve f, causing the latter to move toward the left to the position shown in the front head, d, by the influence of the live steam through the small passage 0, commun cating with the right-hand smaller end of the valve f, as shown in Fig. 2, and when the valve f is moved automatically to such left hand position, as indicated at the front head, at, the auxiliary supply-passage m is closed and communication established from the passage 1% and back end of the cylinder to the passage 19, leading to the auxiliary exhaust 1, that communicates with the main exhaust 7c, and thus the accumulation of pressure is prevented at each end ofthe stroke of the piston a. 0'0, (1, c,f,g, h, l, m, a, 0,p, and q are corresponding parts at the front head of the cylinder, for a similar purpose.

What I wish to secure by Letters Patent, and claim, is-- In combination with the cylinder 1) and reciprocating piston a, the valve-chambers e e and automatic valvesff, arranged respectively within the heads (I d, and having auxiliary steam and exhaust passages, as herein described.

In testimony whereof I have affixed my signature in presence of two witnesses.

SAMUEL G. BRYER.

Witnesses ALBAN ANDRFIN, HENRY GHADBOURN. 

